An analysis of differences in the Polish households' consumption pattern in 2000-2008 was made on the grounds of similarity measures, being modified values of conditional entropy. The present article is an attempt to answer whether, over the time, those differences in the consumption pattern are increasing or declining. Moreover, we shall look at the difference (distance) between the pattern of consumer expenditure made by households in Poland and in the European Union. Consumption pattern have been changing quickly -currently, within a few years, and even within a single year. On the example of consumption patterns of households of young people living in various regions of Poland, we shall show that it is not easy to learn the households' consumption patterns. (original abstract)